1. Field of the Invention
The present invention relates to a TAB (Tape Automated Bonding) type semiconductor device in which a semiconductor chip is mounted on an insulating film, and a method of manufacturing the same.
2. Description of the Related Art
As an LSI (Large-Scale Integrated circuit) packaging method, a so-called TAB method is known. In this method, LSI chips are inner lead-bonded on a tape formed of an insulating resin film on which a conductive pattern is formed.
FIG. 1 is a plan view of a conventional TAB type LSI device. In FIG. 1, reference numeral 11 denotes a film-like tape formed of an insulating resin; 12, lead pattern regions formed by patterning a metal thin film; and 13, LSI chips.
Each lead pattern region 12 is provided with a plurality of leads 14 including inner and outer leads for supplying a power supply potential and inputting/ outputting signals to a corresponding LSI chip 13. Each LSI chip 13 is electrically connected to the distal end portions of the inner leads, each has one free end of a corresponding lead 14 located at the central portion of each lead pattern region 12, by, e.g., inner lead-bonded.
FIG. 2 is a plan view of another conventional TAB type LSI device. In this device, the distal ends of the outer leads each as the other free end of a corresponding lead 14 located at the peripheral portion of each lead pattern region 12 are short-circuited by a short-circuiting conductive pattern 51.
In this structure, even if a high voltage caused by a surge current is applied to any lead 14, the LSI chip can be prevented from electrostatic breakdown since all the leads 14 are kept at an equal potential by the short-circuiting conductive pattern 51.
However, in the structure shown in FIG. 1, the material of the tape can be easily electrostatically charged. Thus, when a metal member of, e.g., a tape feed mechanism is brought into simutaneous contact with a tape surface and lead surfaces during a tape feed operation in, e.g., an operation test mode, a high voltage is applied to leads due to static electricity, and LSI chips are electrostatically broken.
On the other hand, in the structure shown in FIG. 2, since the leads are short-circuited by the short-circuiting conductive pattern, an energization operation cannot be performed.